Muffler



April 23, 1946. G. H. HEDRICK 2,398,788

MUFFLER Filed Jan. 31. 1944 Patented Apr. 23, 1946 -Assayas MUFFLER Gale H. Hedrick, Chicago, Ill., assigner to Maremont Automotive Products, Inc.,

a corporation of Illinois Application January 31, 1944, Serial No. 520,512

2 Claims.

This invention relates to muillers and embodies an improvement which will substantially increase the safety of automotive vehicles with which the muliler is associated.

One of the great dangers present ln all vehicles driven by internal combustion engines is the possibility of the occupants being subject to the ill eilects of carbon monoxide poisoning. It has been found that even small leaks in the exhaust system cause sickness, drowsiness, and often death. Many fatal accidents have been caused by the operator being temporarily overcome by carbon monoxide gas and losing control of the vehicle. l

Ijhave discovered that a cause of this hazard is one which has generally been overlooked. That is to say, when a vehicle is lirst assembled at the factory al1 parts are new and free from rust or damage so that it is not dilllcult to secure a gastight joint between the muiller and exhaust (inlet side of the mulller) or tailpipe (outlet side of the muiller) However. after the vehicle has been driven for some distance and it becomes necessary to replace the muiiier, conditions are diilerent. The connections on the new mulller are round, true, and clean, but the pipe to which it will be attached, such as the exhaust pipe, is often rusted, pitted, and out of round due to corrosion and normal wear of usage.

It is an object of the invention to overcome this dimculty by constructing the muiller with means whereby a self-sealing leak-proof joint may be formed with the tailpipe.

Another object of the invention is to provide a mulller construction in which the means for obtaining the leak-proof joint are extremely simple and do not require any expert mechanical knowledge on the part of the mechanic employed 1 to replace the muiller.

A further object of the invention is to provide a muiller construction which enables a reliable leak-proof joint to be produced which will retain i Figure 1 is a sectional view showing the muiiler broken away and the tailpipe broken away, the two parts being separated but ready for engagement.

, of Figure l in engagement and the sealing material interposed between their co-extensive or telescoping areas.

Figure 3 is a sectional view on the line 3 3 of Figure 2, v

' Figure 4 is a sectional view similar to Figure 2 of a modiilcation,

'Figure 5 is a detailed sectional view of the construction shown in Figure 2,

f\ 1l Figure 6 is a detailed sectional view of the coriy In the construction shown in Figure 1, the tail pipe I5 fits within the connection I2 as shown in Figures 2 and 5, while in Figures 4 and 6, the connection l2 is received within the tail pipe i5.

In order to provide a leak-proofseal which will be reliable and self-sealing, the groove Il or the groove I4' is illled with a. suitable thermoplastic material, preferably one which will (a) flow under heating and (b) set under heating. There are many thermoplastic materials available which will meet these conditions and which will not be aiected by the operation of the vehicle. That is, the sealing material will not corrode the metal members or be dissipated by heat and will not lose its effectiveness in the presence of heat or the exhaust gases.

Preferably, the thermoplastic material is introduced into the groove in a solvent or plasticizer which is volatilized by heating and thereafter the sealing material hardens or soliditles and remains unaffected by the conditions of operation of the motor. l

When the parts have been assembled as shown in Figures 2 to 7, notwithstanding that the tall pipe I5 is rusted, pitted or otherwise deteriorated, operation of the vehicle whereby hot gases pass through the muier and heat the joint Il will cause the thermoplastic material to flow as best shown in Figure 7 to fill in any openings in the Figure 2 is a sectional view showing the parts lioint. As explained, the solvent or plasticizer will be evaporated and the sealing material will solidify in its sealing relation to the respective connections and the joint and this sealed relation will be maintained substantially throughout the life of the muffler.

It is to be understood that the muilier is installed in the regular manner. using present clamps or other conventional means and when the new installation is first subjected to use the parts become warm, the thermoplastic material expands, nlling in all nat spots or points causing leakage and then s ets solidly to effectively seal the Joint against the passage of carbon monoxide and other gases.

With reference to the solvent or plasticizer which may be used to facilitate the introduction and flow of the sealing material, I have in mind a volatile material which will be dissipated when the joint is heated to a temperature of about 200 F. and then the residual material will become solid and remain in that condition without being aflected by heating and cooling within the normal life and the normal use of the muiller. The important characteristics of the sealing material are that it be 1) self-sealing and (2) re main effective to prevent leakage throughout substantially the life of the muiller.

The muiller may be supplied with the sealing material in the groove i4 or i4' so 'that it is only necessary to introduce the tail pipe so as to form a joint and thereafter the leak-proof seal is automatically .formed in the operation oi the vehicle.

The assembly shown in Figure 2 may also be made as a unit to include lthe muffler with its connection, the tail pipe and this sealed joint between the intertting pipe and connection.

The tubular intertting connections I2 and i5 are readily detachable sincethe sealing material iB is not necessarily adhesive but simply has the qualities above set forth ot owingin a manner to close any deciivities or openings in the Joint to thereby seal the same and form a permanent gas-tight joint which is unaiiected by temperature changes either produced from operation oi the motor or occasioned by seasonal changes in climate.

While the groove to receive the sealing material may be formed in the exhaust pipe II, it is preferable to iorm the same in the muiiier outlet connection i2 as shown.

In some cases only the outlet connection I2 requires replacement and in that event, it is simply necessary to provide the mumer with a new end il or a new connection I2 constructed as shown and described herein.

It will be noted upon reference to Figure '7 that the sealing material is present in the groove forming the joint between the connection i! and the zvlpe I5 and that the sealing material flows in a manner to be disposed between the adjacent contiguous areas oi the lnteriltting pipe and connection and form a continuous sealing layer enclosed by the pipe and connection.

claim:

l. As a new article of manufacture a muiiier for internal combustion engines having a reduced end for connection to a pipe, said end con nection 'being provided with an annular groove having a sealing material disposed therein, said sealing material being heat responsive to the extent that hot engine exhaust gases passing through the pipe and the muiiler modify the sealing material to produce a seal between the pipe and the reduced end of the muler.

2. As a new article of manufacture a muiiler for internal combustion engines according to claim l, wherein a pipe is telescoplcally oonnected with said'reduced end oi the muiller and overlaps said groove and the sealing material disposed therein.

GALE H. HEDRICK. 

